Synthesis,characterisation and performance of nanosilica as filler in natural rubber compounds

Low particle size silica in the nanometer range was synthesised in an aqueous medium by the sol-gel method using dilute hydrochloric acid and sodium silicate,and characterised using x-ray diffraction (xrd),scanning electron microscopy (sem) and infrared spectroscopy (ir). this synthetic nanosilica had a lower number of hydroxyl groups than commercial silica and hence underwent reduced silica-silica agglomeration. the nanosilica was used as a reinforcing filler in natural rubber compounds,its cure characteristics and mechanical properties were evaluated. minimum torque,maximum torque,scorch time and cure time were increased with silica loading. mechanical properties such as tensile strength,young's modulus,tear strength,abrasion loss,hardness,resilience and compression set were better than those of natural rubber vulcanisâtes filled with commercial silica. volume fraction of rubber in a solvent-swollen sample was also higher for the nanosilica compounds.